I have embarked on a mission to paint all of the round things in the solar system and I am taking you with me. The round things are the big and old things, so they tend to be pretty good. In this part we are going to journey for two hundred and fifty million miles. To make it easy I am going to pretend that all of the things are in one big line and refer to one as being after the other, although it actually looks more like someone sneezed on their record player.
We start in the middle, and you know what that means…
The sun is an enormous and terrifying roiling ball of magnetic plasma that lives in the middle. the sun’s main task is to turn 600 million tons of hydrogen into 596 million tons of helium a second. The remaining 4 million tons of hydrogen a second is turned into all of the energy that the sun spits out. 0000002% of that energy gets to us but 30% of that 0000002% is reflected back into space by the Earth’s atmosphere. The total solar energy absorbed by Earth in an hour is more than people use in a year. The sun is a monster.
36 million miles after the sun is:
Mercury is the dinkiest “real” planet and is a blasted grey rock with a massive magnetic metal middle. If you went to Mercury in the day you would be immediately cooked like a broiler chicken and if you went at night you would be immediately frozen like Iceland chicken breast fillets. This is because Mercury has no atmosphere. The sun looks 4 times bigger there than it does from Earth. Spacecraft MESSENGER has been hanging out and keeping it company for the last few years.
26 million miles after Mercury is:
Venus is the brightest thing in the sky at dusk and dawn. You can’t see it at proper night cos it lives near the sun. It is the goddess of love because it has a thick reflective sulfuric acid shell that covers dense liquid carbon dioxide clouds and it is absolutely roasting hot. The surface is bone dry smooth volcanic plain except for two upland continents, one the size of Australia and one the size of South America.
24 million miles after Venus is:
239 thousand miles after Earth is:
“The moon” is the first, and therefore most important, moon in the solar system. We should be grateful that we have a nice moon. Mars has rubbish moons. Mercury and Venus have none. Our moon is the largest in the solar system relative to its planet but we are not a double planet system because the moon is locked to the Earth, which is why the same side always faces us. If we were a double planet then one side of the Earth would face the moon the whole time too and we would be dancing like Rose and Jack on the Titanic. Although romantic and exciting, this would mean that half the planet wouldn’t be able to see the moon and that would affect property prices.
34 million miles after Luna is:
Mars is our future home and is therefore of great interest. There are five vehicles currently scrutinising Mars. There are three orbiters and Curiosity lab and the crude rover Opportunity are on the surface and they all have multiple twitter accounts and take awesome pictures. Water vapour clouds like on Earth form on Mars when spring sunlight touches the frozen carbon dioxide that covers the water ice at the poles, the carbon dioxide turns straight to gas and rockets off the ice cap into the sky at 250mph, taking water with it.
115 million miles after Mars is:
Ceres is the largest object in the asteroid belt between Mars and Jupiter. It is the size of Texas and may hold more water than is on the whole Earth. It is close enough to the sun for the ice to melt and reform and it periodically coughs water into its atmosphere. It could be smuggling life stuff. Dawn spacecraft will be there in a year to check it out. Dawn spacecraft is cool because it uses an innovative Ion Propulsion System that works by exciting Xenon atoms using a captive musical ninjutsu space pixie:
And we all wish him well.
Well, that’s as far as we can go for now. Here is a good size comparison of everywhere we’ve been so far. Next time we’ll be jetting off to Jupiter to have a look at it and its moons and stuff.